Science of the Times: Studies on memory you'll not soon forget

Boy did you guys ever dodge a bullet this week. I very nearly did a whole column about patent law related to synthetic DNA, but I just couldn’t get it together in time.

The impetus for that column (which, rest assured, I will get to in a couple weeks) was the announcement out of the Scripps Research Institute in La Jolla, Calif., where biologists say they have Frankensteined an E. coli bacteria by adding two synthetic nucleotides to the normal four base pairs of DNA (A, C, G and T).

This is obviously momentous news with some pretty arresting ethical implications that hopefully won’t get lost like teardrops in the rain (to borrow from Roy Batty), but I’ve still got to talk to some folk with a keener insight into all this than I have, so let’s put that aside for the moment and look at what Roy was talking about in that famous scene from “Blade Runner:” Memory.

The word typically conjures recall of prior events or experiences, but has also in recent years been applied to “memory materials” capable of self-repairing damage to structures using specialized polymers.

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These are typically useful only up to a very small point, but researchers at the University of Illinois say they have created a new type of plastic capable of repairing large cracks and even bullet holes with a fast-hardening gel.

The system was reportedly inspired by the way blood coagulates to cover up wounds when it hits open air, according to a story in XXX. “Veins” in the plastic material deliver two chemicals in liquid form to the site of the damage, where they mix and create a polymer that restores the structural integrity of the host material. Think of those double-barreled epoxy syringes you see at the hardware store where two separate tubes feed into a single opening.

So far, this has been demonstrated only in lab settings where the stuff is fed to the affected area, but the idea is to develop materials with the bonding materials preloaded, capable of responding automatically to damage.

The Defense Advanced Research Projects Agency, more commonly known as DARPA, is meanwhile busy trying to fill in a very different kind of gap: That left behind by the horrors of war.

According to a report in AFP, DARPA will soon unveil a “neuroprosthetic” brain implant capable of stimulating the hippocampus to restore declarative memories; those associated with people or past events that might have been lost due to the kind of brain trauma soldiers experience in combat.

Details about the project are sketchy at best, though it appears to be premised on a similar method of treating Alzheimer’s and Parkinson’s patients where electricity is pulsed directly into the brain.

In order to “recover” lost memories, however, DARPA scientists are going to have to find a way to mimic the specific patterns and connections associated with the memories they seek to restore. If they can manage to overcome that obstacle, the potential for this tech could be huge.

Researchers at the Hospital for Sick Children in Toronto have also been exploring a different stage of memories — those that develop in the first few years of life.

I couldn’t say with any amount of certainty what my first memory is, but it certainly wasn’t my first birthday, or even in the first few years of my life.

That’s because humans experience something called “infantile amnesia,” the inability to remember anything until they’re about 2 to 4 years old.

The reason for this is thought to be a flood of neurons produced in the hippocampus early in life, which essentially sweep out old memories as they are replaced by new experiences.

For many species, this process ends fairly quickly after birth, but humans (and luckily mice) continue to produce neurons throughout their lives, a process that tapers off with age.

According to a report in Nature, the husband-and-wife team of Sheena Josselyn and Paul Frankland has found that normally developed infant mice who received electric shocks from the floor of a test chamber would completely forget the experience given 24 hours. You could put them back in there two or three days later and they’d bumble around as though they had never seen the place.

Adult mice, on the other hand, would remember the environment and freeze up as soon as they were put back in the chamber.

Now, here’s the interesting part: Infant mice whose neuron development had been artificially suppressed recalled the shocks for up to a week and responded much like their adult counterparts. This would indicate that heavy neuron production aids in essentially “overwriting” older memories, hence our inability to recall our earliest days.

Obviously, you couldn’t repeat these experiments in humans, which is a shame, especially for those of us with exceptionally poor memories. I’m constantly told that I’ve seen movies or had conversations that I have no memory of whatsoever, even after just a few days or weeks.

It could simply be that my brain is tabbing those things as trivial — giving them no more weight in long-term data banks than a daily commute or unexceptional burrito — but I would be curious to see if it’s actually a function of my hippocampus continuing to produce a higher-than-average amount of neurons for a person my age.

Which reminds me of a rather neat little quirk of memory known as the “oddball effect.”

Think of the last time you narrowly avoided a traffic accident. Remembering it now, it might seem as though time slowed down when you hit the brakes and swerved.

The reason for this is that while your brain would normally disregard most information during the drive as unimportant (unless you have hyperthymesia, the ability to remember literally every moment of your day for years) this instance was ranked “super important,” and so your brain recorded each and every second, stacking them one on top of the other so as to give the impression that time was stretching out.

There are several competing theories about this phenomenon, one of which argues that we experience it in real time so as to provide the best possible chance of survival. Another claims that it is more a function of recall rather than “in the moment” situational awareness.

Regardless, it would seem that the best way to ensure memory retention is to walk around terrified all the time. That might sound like a tall order, but I think I’ve got the solution: We just electrify all the floors.

Alex Rose covers the Delaware County Courthouse for the Daily Times. Follow him on Twitter at @arosedelco. Check out his blog at delcoscience.blogspot.com. Email him at delcoscience@gmail.com. His column appears every Tuesday.

About the Author

Alex Rose covers court proceedings for the Daily Times. He also writes a weekly science column. Reach the author at arose@delcotimes.com
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